Method of welding and brazing the seams of metal tubes.



M. B. LLOYD. METHOD 0E WELDING AND ERAZING THE sEAMs 0E METAL TUBESEAPPLYIUATION FILED APB.. 6, 1912.

Patented Jau 5, 19M.

E. pl 23933@ 4 SHEETS-SHEET l.

y m. B. mmm.- METHOD 0F WELDING ND BBAZING THE SBAMS 0F METAL TUBES.

PPLIGATION' Hmm Arme, 1912.

Patented Jan. 5, 1915.

4 SHEBTS-BHEET 2.

mar mit' M. B. LLOYD. kMETHOD 0F WELDING AND BRAZING THE SEAiMS 0F METALTUBES.

APPLIOATION FILED Arme, 1912.

Patented Jan. 5, 1915.

M. B. LLOYD. METHOD OP WELDING AND BRAZING THB SBAMS 0F METAL TUBES.

APPLICATION FILED APR. 6. 1912.

Patented Jan. 5, 1915.

4 SHEETS-SHBET 4.

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a resident of Menominee, county of UNITED STATES PATENT OFFICE- MARSHALLBUR-NS LLOYD, 0F MENOMINEE, MICHIGAN, ASSIGNOR, BY MESNE ASSIGN- MENTS,TO THE ELYRIA IRON TION OF OHIO.

& STEEL COMPANY, OF EYRIA, OHIlO, A CORPORA- METHOD OF WELDING ANDBRAZING THE SEAMS OF METAL TUBES.

Specification of Letters Patent.

Application filed April 6, 1912. Serial No. 689,095.

To all 'whom it may concern.'

Be it known that I, MARSHALL BURNS LLOYD, a citizen of the UnitedStates, and

nominee, and State of Michigan, have invented a certain new, useful, andImproved Method of lVelding and Brazing the Seams of Metal Tubes, ofwhich the following is a full, true, clear, and eXact description, suchas will enable others to make and use the same.

My invention relates -to improvements in the art of closing the seams ofmetal tubes and has special reference to improvements in methods ofwelding or brazing the lon gitudinal joints or seams of metal tubes.

The object of my invention is to improve present methods of brazing andwelding metal tubing and tov produce welded metal tubing of line qualityat low cost.

The further object of the invention is to provide a machine which shallbe capable of continuous operation and which shall be adapted to rapidlyand economically weld or1 close .the seams of metal tubes by means ofheat and the addition of metal such as brass or steel.

My invention `resides in certain novel steps or operations in thewelding of metal tubing and also resides in apparatus by means of whichsaid novel steps may be carried out in a practical manner. The steps oroperations referred to are performed upon tubing which has beencompleted up to the point. of closing the seam thereof. As a first stepl. place between the opposed seam edges of the tube a small strip ofmetal like unto that composing the tubing, when it is desired that thetubing shall be of uniform composition; or of a different kind, whenanother metal will better serve the purpose and is not objectionable.The strip is of greater width than thethickness of the tubing and I solocate the strip between the edges that it projectsfrom the surface ofthe tube after the manner of a continuous longitudinal rib thereon.Having prepared the tubing in this manner, edges and the strip together.This I accomplish by means of an intense, localized welding or fusingheat applied progressively. The fusing is started at one end of the tubeand by longitudinal movement of the tube with respect to the heater ortorch I weld the seam is continued until the other end of the seam isreached. The projecting edge of the small strip is melted andpractically removed and merged with the surface of the tube. lVhere thetubing and the strip are composed of different metals, as in the case ofa tube of steel and a strip of brass, the welding or fusing is commonlyreferred to as the act of brazing, and the completed tubing is known asbrazed tubing.

One preferred step of my invention consists 1n using the inserted stripas a guide to accurately aline or position the seam and the Welder' forthe purpose of insuring uniformity in the welded seam.

My novel machine or apparatus, for carrying out the foregoing steps, hasa tube holding mechanism that is adapted to hold or press the seam edgesof the tube firmly upon the inserted strip and at the same timelongitudinally move the tube as a whole at a speed which is constantfrom the moment of starting to the moment of the completion of the weld.A Welder, preferably a gas blow pipe or torch is so positioned as to diVrect its iiame upon the seam of the tubing during the entirelongitudinal movement thereof. The machine, from an operativestandpoint, is completed by a seam and torch positioning device whichacts through the medium of the inserted strip while the tube is inmovement, and obviously, before the strip is melted down by the torch.

My invention also consists in various novel constructions andcombinations of parts, all as hereinafter described and particularlypointed out in the appended claims. f

The invention will be more readily vunderstood by reference to theaccompanying drawings forming part of this specification, and in which:

Patented Jan. 5, 1915.

Figure 1 is a side elevation of my novel apparatus or machine, adaptedto the performance of the several steps of the method hereinbeforebriefly described; Fig. 2 is an enlarged plan view of the machine, thewelder beingremovedy to more clearly disclose other parts; Fig. 3 is atransverse vertical section of the machine, on theline 3-3 of Fig. 1;Fig. 4 is an enlarged detail, being a transverse section on the line4.-4: of Fig. 2, showing the tube in position between two jaws of theholding and propelling section of the machine and about to be graspedthereby; Fig. 5 is a similar view on the line 5 5 of Fig.- 2, showingthe tube as it appearswhen clasped and in movement; Fig.- 6 is anenlarged longitudinal vertical section 'on the line 6-6 of Fig. 2,disclosing the details ofthe tube positioning device; Fig. 7 Y is anenlarged sectional detail on the line 7-'7 of Fig. 6; Fig. 8 is aperspective view'of a short length of tubing showing the welding stripinplace between the seam edges of the tube; and Fig. 9 is a similar Viewshowing the tube as it appears after it is welded.. y

vAs explained, my invention applies to preformed tubing having a seam tobe closed.` Tubing of this character is usually formed upf-from a ilatstrip by'a longitudinal rolling processor by drawing the strip throughforming dies. The tube resulting from this process has a longitudinalseam or crack, formed by the edges of thel strip, the seam being in amore or less open condition according to manner in whichfthe tubing ismade. It is the purpose of my invention to unite these edges andpermanently seal or close this seam, thereby rendering the tubecircumferentially integral and imparting to it practically all of thecharacteristics of the so-called seamless or drawn tubing.

In the forming of the tubes various conditionsf'make it difiicult toconfine the seam edges'to a straight line andthe seam is y generallymore or less wavy or irregular,

frequently assuming a spiral form, Tol correct these irregularities nadvance of actual welding I adapt the machine, to grasp one force on thefree part of the tube and thereend of the tube *and then exert atwisting .by straighten the seam 'so that the tube will travel towardthe Welder with its seam in very exact alinement therewith. V

The essential or principal elements of the particular machine shown inthe drawings are a heating -device A, such as an oxyacetylene torch,positlonedto impmge a flame upon the tube seam; a tube propelling anism,to properly position the seam in alinement with the burner fiame,without inter rupting the movement of the tube. All vof these parts aremounted-and coperativelyl related on a suitable bench or'frame D.

The tube propelling mechanism performs certain vfunctions inconnectionwith the positioning of 'the seam and it acts to hold the added metaland the edges of the tubing togethers-with a sufficient grip or pressureto .on said pla e.

maintain theseparts in fixed relation while the welding proceeds. Thetube propelling mechanism Bris in the form of a' rotary or continuousvise composed of'many succes-A the tube without crushing it and hold theThe sections or l seam until it sets or,cools. vise jaws are carried bytwo parallel endless chains B? running over the forward and rearsprockets B3 and B1. Each section comprises a pair of opposed blocksmounted' upon parallel twin rods `B5 which extend between and aresecured to the chains, the blocksof each section being movable laterallythereon so that they will close and open at the proper times (Figs. 4and 5). Each pair bf jaws if normally held open 'by means o f a springpressed pin B extending between and entering-holes or sockets inthe viserotates, the jaws freely clear the tuber at the discharge end of themachine and likewise at the intake end. (See Figs. 1 and 2). Thegripping portions of these sections.

are small, easily removable blocks B7 having gripping surfaces B8 whichconform to the shape of the tube and which-expose preferably only asmall portion of the metal edges T1 contiguous to the seam, as clearly'shown jaws, as clearly shown in Fig. 4, and as Athe in Figs. '4 and 5.,As the vise sections rise into active zalinement they close' upon and,-gr1p successive portionsvl of the incoming 105 tube, firmly holdingthetube while propelling it forward beneath the flame from the burner. 'Y

The gripping action of the vise is brought about automaticallyl bymechanism which causesthe sections toclose upon and successively clampthe tubeas they rise into,

alinement therewith. This mechanism, as

here shown, is in the form of a long channel deiining the active portionof the vise. The

"bottom of thi channel is formed by the'bed plate B9 of t e machine andthe side wallsV thereof are formedby. long bars or cam members B1o andB11- adjustably mounted Each vise .jaw is provided Witho'ne or moresmall, anti-friction rollers cam faces B11 and B1i respectively of thecam' bars, to reduce the'y friction between B17 located between the jawsat the dis'-` 1-20 '1312.1' These bear upon the adjacent inner charge.end of the vise. The vcamA members nuts B21. Both cam bars may beadjusted to a nicety by means of set screws B22 and B28 respectivelycarried in lugs B2'2 upstanding from the plate B9. Cushion springs B25are interposed between the set screws B23 and the outer face of cam barB11. This manner of arranging the cam members provides for adjustablecompressive force at all times justfsuiiicient to cause the vise toproperly grip ythe tube. The chain sprockets B3 and .Bt are mounted uponshafts B26 and B27 re:

spectively journaled in bearing standards B2s which" rise from the frameof the machine.` Iregulate the tension of the vise chains 'or belts bymeans of idler sprockets B29, which are vertically adjustable in theirshaft bearings B3o by the screws B31. The

vise is driven at a constant speed from the. main shaft B32 through thetrain of gears B32.' connected to the rear shaft B27 of the vise. 'Ihevvintermediate gear B34 of this train is carried upon a 'swinging arm B35serving as a starting and stopping device v travels.` l

may be provided for this tank to maintain for the machine. The mainshaft is driven .from 4a countershaft B36 by any suitable f heat oftheltorch or burner A is communicated to the vise sections and to properlycool these parts I employ a water tank B38 below...thebed plate, throughwhich the lower or. inactive portion of the rotary vise Suitable supplyvand `drain pipes a' circulation of water therein.

The preparation of the tube for brazing or welding consists in putting athin, narrow metal strip T2 between the edges of the tube T. vThe stripis so-placed that it projects from the surface of the tube far enough toform a controlling rib or ridge, as shown in Fig. 8. After being placedin the seam the strip is maintained in position by the resilientpressure of the edges T1. lLater on the vise forcibly presses the tubeedges tightly together, holding the strip firmly therebetween. The'brazing or welding strip follows the irregularities in the seam and asthe tube travels forward, this rib, in conjunction with the vise andlgrooved guide C1, about to be described, ef-

fects a twisting or torsional movement of the tube, the result beingthat the tube seam is automatically reformed or straightened as the tubetravels and the seam is thereby positioned in line with the burnerflame.'

`set screw C5. At the forward end of the machine frame, I provide anupstanding bracket D1 and thereon a shelf D2 which serves as apreliminary guide for properly supporting the tube in position to enterthe machine. This guide and the vise hold the tube rib in the guideblock C1. The bridge also has a rearwardly extending arm C6 positionedimmediately above the tube and carrying at its free end a pairof spacedheat localizers C7 by which the'flame of the burner is confined to thetop of the tube as clearlyy shown in Fig. 6.

Any suitable electric or gas heating device may be employed forsupplying the necessary heat, but I find that very satisfactory resultsmay be obtained by the use ofan oxy-acetylene torch A. This torch isarranged to emit a flame, composed of proportionate quantities of oxygenand acetylene gas. which plays upon the seam of the tube as it passes. Imount this torch above the vise, preferably about midway, the nozzle A1of the torch being pointed diagonally downward in the direction of theapproaclr` ing tube. The torch has a gas mixing chamber A2 and gaslducts A3 which are connected to the flexible supply pipes A4. The

-gases are controlled by the valves A5. I.

mount this torch upon a swingable lever A, the downward movement ofwhich is limited by stops. By grasping one lever A6 the torch may beswung upward out of the way of the tube, for purposes of inspecy'tionand repair, as clearly shown in Figs. 1

Aand 3. This lever is laterally adjustable on an upstandingframe'coniposed vof a horizontal rod or bar A7 and uprights A8, and

the torch is also revolubly adjustable in the lever A6. By theseadjustments the nozzle may be caused to project the llame midway on theseam to heat the tube edges equally as required for the best and vmostrapid weldin It w1ll be understood that the rotary vise is normally inmovement and the torch is normally lighted. j

To use the machineA the operator first i places a narrow-welding stripT2 in the seam slit of a tube T and then inserts the end of the tube inthe guide D2. In so doing the operator takes care to put the end of thevise. tube andforce the edges thereof against the In this manner theseam is accurately. posistrip or rib D2V of the tube into the guidinggroove of the block C1. 'Ilie tube is then pushed forward until its endis caught by" the vise jaws. From the moment that this occurs `the tubetakes on a constant speed of movement, being drawn lin by, the rotaryObviously the vise jaws squeeze the interposed or added metal strip. Theguide block groove is in line .with the .center line of the series ofvise jaws constituting the active portion orstretch of the vise andtherefore when the end of the tube is grasped by the vise the seam willbe found to be quite exactly in a vertical plane including said centerline of the vise. Rotation Vof that portion of the tube in the visecannot 'take place because of the grip of the vise l jaws hence if thefree portion o f the tube' is twisted it must yield to the alininginfluence of its rib 'I2 'and the guide block C1.

tioned in the vise and ust needs travel for- "ward in' proper relationto the torch. As before stated, the torch is adjusted to play upon theseam midway between the jaws of the vise and midway of the ends of thevise. When the forward end of the tube reaches the torch'the heatthereof, being localized upon a very small part Aof the seam edges,quickly reduces the same and the strip to a substantially molten stateand as theseA portions are positively held togethervinfthe vise theyinstantly imite and become as one part.

' Thespeed of the vise is determined by the rate at which the heat ofthe torch willweld `the seam; andas the tube moves beneath the torch,`the seam is progressively welded. Though the metal is heated to a highdegree at the welding point, it will be noted that on v passing the`torch the hot metal is exposed to serts another and butts the endthereof cool air and this, coupled with. the rapid absorption of theheat by the ,relatively mas sive vise jaws, causes the cooling orsetting of the weld almost at once after leaving the torch. When the.end of one tube disappears through the guide D2, the operator inagainstthat of the tube in the machine so terruption.

that the welding process'goes on'withoutin- ',As herein shown, anddescribed my invention is employed in welding comparatively short tubes,but I desire that it be understood that the invention is equally welladapted for employment in such continuous tubing processes as I haveshown and" described in my pending application Serial Number. 638,202filed, July 12, 1911. In lsuch cases the tubing is formed from the flatstock and instead of placing the brazing strip in the whole length oftubing as herein depicted, I feed the strip into the seam` as fast asthe tubing is formed. v

` As various modifications of my invention will readily suggestthemselves to one skilled in the art, I do 'not confine the inventiontothe steps or mechanisms herein specifically described. .l

Having thus described' my invention, I

claim asnew and desire to secure by' Letters Patent:v l l s 1. Theherein described improvement in 'the artfofimanufacturing tubing thatcontube a metal strip of such width as .to form an external rib on saidtube, `moving said tube longitudinally'and subjecting the seam edges totransverse pressure, directing said seam edges in a straight linebymeans of said rib and applying welding'jheat locally to said strip andseam edges as the tube moves forward, thereby welding the seamprogressively, substantially as described.

In testimony hereof, I have hereunto set'r my hand this 11th day ofMarch, 1,912, in the presence of two subscribing witnesses.

' MARSHALL BURNS LLOYD.l

Witnesses:

j HiLnA C.' fPE'riiRsoN, l Catas'.r GILBERT HAWLEY.

